Form Chair by Kartell. Form is ideal for both home and business use. The basic element of the Form series is a seat created from a sheet of semi-structural polyurethane that lies on a light, chromed steel structure. It has a wide and comfortable seat, which shows the result of meticulous research into the thickness of the material. This research has enabled a reduction in thickness to only 1 inch, without compromising solidity, resistance or flexibility. The series can be expanded by placing the armchairs side by side to form long benches. Form Chair by Kartell are designed by Piero Lissoni.